Commutator



May 22, 1962 V K. e. L. KALLlN ET AL COMMUTATOR Filed June 28, 1960 FIG. 2

FIG.3

INVENTORS KURTGOSTA LEOPOLD KALLIN LARS ALFRED LINDBLAD ATTORNEYS United States Patent 3,036,165 COMMUTATOR Kurt Giista Leopold Kallin, Karlskoga, and Lars Alfred Lindblad, Klinten, Sweden, assignors to Aktiebolaget Bofors, Bofors, Sweden, a Swedish company Filed June 28, 1960, Ser. No. 39,399

Claims priority, application Sweden July 1, 1959 4 Claims. (Cl. 200-26) The present invention refers to a commutator of the type in which a number of segments made of electrically conducitng material form parts of a cylindrical surface, each segment then being in electrically conducting contact with its slip ring arranged concentrically in relation to the said cylindrical surface.

In previously known commutators of the said type, the connection between each segment and the corresponding slip ring consists of a wire connection. The said wire connection complicates the manufacture to a high degree and is not desirable if there are very rigid requirements for trouble-free operation.

The purpose of the present invention is to create a commutator of the said type in which the wire connections can be avoided. This is achieved according to the invention in that each segment comprises a part of the cylindrical surface of the corresponding slip ring or a part protruding from the cylindrical surface of the said slip ring.

In the following the invention will be described more in detail with reference to the attached drawing in which FIGURE 1 shows in perspective the electrically conducting parts in a commutator according to the invention separated from each other, in which FIGURE 2 shows in perspective a commutator according to the invention built up with the parts shown in FIGURE 1 with brushes connected, and in which FIGURE 3 shows a side View of the commutator shown in FIGURE 2.

In FIGURE 1 four parts 1, 2, 3, and 4 are shown, of which parts 1 and 4 and parts 2 and 3 have been made in identical pairs. Each part comprises a cylindrical slip ring surface 5 and a commutator surface 6. The surfaces 6 comprise parts of a cylindrical surface and have the same arc radius. The parts 1 and 4 are cylindrical internally and have an internal diameter which is greater than the external diameter of the slip ring parts of parts 2 and 3. Parts 14 which consist of platinized brass are fastened together with the aid of epoxy resin, which has been designated 7 in FIGURES 2 and 3.

In FIGURES 2 and 3 the reference numbers 9-14 designate a number of brushes, of which 11 and 14 are in contact with the commutator surface, while on the other hand, the others are each in contact with its slip ring surface.

The commutator described functions in the following Way. It is assumed that the commutator turns clockwise in FIGURES 2 and 3. An impulse which is fed to the brush 11 can be taken out over the brush in the position shown. When the commutator has been turned 45 from the position shown, but before it has been turned 135, the impulse can be taken out over the brush 13. Thereafter it is taken out over the brush 12 and finally over the brush 9. Impulses which are fed to the brush 14 are commutated in the same way with 180 displacement.

The invention is of course not limited to four parts of the commutator, but both a greater and a lesser number of parts can be used. Also the number of brushes which are in contact with the commutating part can be varied.

the sleeve portion of the first member and the outer di- 4 ameter of the segmental cylindrical portion being equal to the outer diameter of the cylinder segment of the first member, the circumferential length of said cylindrical portion of the second member being less than the circumferential length of said cut-out, said second member being nested in the first member coaxially therewith, the widened segmental portion of the second member being circumferentially centered in the cut-out of the first memher.

2. A commutator according to claim 1 wherein said two members are secured in positions relative to each other and electrically insulated from each other by a hardened insulation material filling the spacings between said members.

3. A commutator including two pairs of a first electrically conductive member and a second electrically conductive member, the first member of each pair comprising a cylindrical sleeve having a circumferentially elongated cut-out at one end to form a cylinder segment at said end, said cylinder segment constituting a commutator surface and the full portion of the sleeve a slip ring surface, and the second member of each pair comprising a cylindrical sleeve portion and a widened segmental cylindrical portion, the latter extending from one end of the cylindrical sleeve portion of each second member, the outer diameter of the sleeve portion being less than the inner diameter of the sleeve of the first member and the outer diameter of the segmental cylindrical portion of the second member being equal to the outer diameter of the cylinder segment of the first member, the circumferential length of said cylindrical portion being less than the circumferential length of said cut-out, the first members of the two pairs being coaxially disposed, the cylinder segment of each first member engaging the cut-out of the respective second member in diametrically opposite relationship, and each of the second members being coaxially nested in the respective first member, the widened segmental portions of the two second members each protruding into said cut-outs and being centered between the cylinder segments of the first members.

4. A commutator according to claim 3 wherein said four members are secured in positions relative to each other and electrically insulated from each other by a hardened insulation material filling the spacings between the members.

References Cited in the file of this patent UNITED STATES PATENTS 1,056,739 Davis Mar. 18, 1913 1,294,894 Froorn Feb. 18, 1919 1,661,923 Clay Mar. 6, 1928 2,133,980 Fowler Oct. 25, 1938 2,164,964 Topalow July 4, 1939 

